Friday, December 9, 2016

Cornell researchers have discovered a biological mechanism that helps convert nitrogen-based fertilizer into nitrous oxide, an ozone-depleting greenhouse gas. The paper was published online Nov. 17 in the Proceedings of the National Academy of Sciences.

“The first key to plugging a leak is finding the leak,” said Kyle Lancaster, assistant professor of chemistry and chemical biology, and senior author on the research. “We now know the key to the leak and what’s leading to it. Nitrous oxide is becoming quite significant in the atmosphere, as there has been a 120 percent increase of nitrous oxide in our atmosphere since pre-industrial times.”

Lancaster, along with postdoctoral researcher Jonathan D. Caranto and chemistry doctoral candidate Avery C. Vilbert, showed that an enzyme made by the ammonia oxidizing bacterium Nitrosomonas europaea, cytochrome P460, produces nitrous oxide after the organism turns ammonia into an intermediate metabolite called hydroxylamine.

N. europaea and similar “ammonia-oxidizing bacteria” use hydroxylamine as their fuel source, but too much hydroxylamine can be harmful – and the resulting production of nitrous oxide is a chemical coping strategy.

Lancaster and his colleagues hypothesize that when ammonia-oxidizing bacteria are exposed to high levels of nitrogen compounds, such as in crop fields or wastewater treatment plants, then nitrous oxide production via cytochrome P460 will ramp up.

In the atmosphere, greenhouse gases are a soup of many species, and Lancaster explained that nitrous oxide has 300 times the potency of carbon dioxide. “That’s a staggering number,” he said. “Nitrous oxide is a really nasty agent to be releasing on a global scale.”

Lancaster added that nitrous oxide is photochemically reactive and can form free radicals – ozone-depleting agents – which aggravates the issue of blanketing Earth’s atmosphere with more gas and raising the globe’s temperature. “In addition to its role as a greenhouse gas cloak, it’s removing our protective shield,” Lancaster said.

The United States is among the world leaders in importing nitrogen fertilizer, according to the U.S. Department of Agriculture’s Economic Research Service. The Food and Agriculture Organization of the United Nations noted that the world’s nitrogen fertilizer demand was projected to be 116 million tons for this past agricultural season.

“For the world, I realize that we are trying to feed more people and that means more fertilizer – and that means more nitrous oxide,” said Lancaster, who noted that about 30 percent of nitrous oxide emissions come from agriculture and its accompanying land use.

To reduce the negative impact of nitrogen, farmers already use nitrification inhibitors.

Said Lancaster: “While it will be challenging to develop ways to stop this process, now we have pinpointed one biochemical step leading to nitrous oxide production. Future work may lead to inhibitors, molecules that can deactivate or neutralize this bacterial enzyme. Alternatively, we may just use this new information to develop better strategies for nitrogen management.”

The Department of Energy Office of Science and the National Institutes of Health supported the research.

Thursday, November 3, 2016

Date: November 2, 2016Source: Pacific Northwest National LaboratorySummary: It may sound like science fiction, but wastewater treatment plants across the United States may one day turn ordinary sewage into biocrude oil, thanks to new research. The technology, hydrothermal liquefaction, mimics the geological conditions Earth uses to create crude oil, using high pressure and temperature to achieve in minutes something that takes Mother Nature millions of years.

It may sound like science fiction, but wastewater treatment plants across the United States may one day turn ordinary sewage into biocrude oil, thanks to new research at the Department of Energy's Pacific Northwest National Laboratory.

The technology, hydrothermal liquefaction, mimics the geological conditions Earth uses to create crude oil, using high pressure and temperature to achieve in minutes something that takes Mother Nature millions of years. The resulting material is similar to petroleum pumped out of the ground, with a small amount of water and oxygen mixed in. This biocrude can then be refined using conventional petroleum refining operations.

Wastewater treatment plants across the U.S. treat approximately 34 billion gallons of sewage every day. That amount could produce the equivalent of up to approximately 30 million barrels of oil per year. PNNL estimates that a single person could generate two to three gallons of biocrude per year.

Sewage, or more specifically sewage sludge, has long been viewed as a poor ingredient for producing biofuel because it's too wet. The approach being studied by PNNL eliminates the need for drying required in a majority of current thermal technologies which historically has made wastewater to fuel conversion too energy intensive and expensive. HTL may also be used to make fuel from other types of wet organic feedstock, such as agricultural waste.

Using hydrothermal liquefaction, organic matter such as human waste can be broken down to simpler chemical compounds. The material is pressurized to 3,000 pounds per square inch -- nearly one hundred times that of a car tire. Pressurized sludge then goes into a reactor system operating at about 660 degrees Fahrenheit. The heat and pressure cause the cells of the waste material to break down into different fractions -- biocrude and an aqueous liquid phase.

"There is plenty of carbon in municipal waste water sludge and interestingly, there are also fats," said Corinne Drennan, who is responsible for bioenergy technologies research at PNNL. "The fats or lipids appear to facilitate the conversion of other materials in the wastewater such as toilet paper, keep the sludge moving through the reactor, and produce a very high quality biocrude that, when refined, yields fuels such as gasoline, diesel and jet fuels."

In addition to producing useful fuel, HTL could give local governments significant cost savings by virtually eliminating the need for sewage residuals processing, transport and disposal.

"The best thing about this process is how simple it is," said Drennan. "The reactor is literally a hot, pressurized tube. We've really accelerated hydrothermal conversion technology over the last six years to create a continuous, and scalable process which allows the use of wet wastes like sewage sludge."

An independent assessment for the Water Environment & Reuse Foundation calls HTL a highly disruptive technology that has potential for treating wastewater solids. WE&RF investigators noted the process has high carbon conversion efficiency with nearly 60 percent of available carbon in primary sludge becoming bio-crude. The report calls for further demonstration, which may soon be in the works.

PNNL has licensed its HTL technology to Utah-based Genifuel Corporation, which is now working with Metro Vancouver, a partnership of 23 local authorities in British Columbia, Canada, to build a demonstration plant.

"Metro Vancouver hopes to be the first wastewater treatment utility in North America to host hydrothermal liquefaction at one of its treatment plants," said Darrell Mussatto, chair of Metro Vancouver's Utilities Committee. "The pilot project will cost between $8 to $9 million (Canadian) with Metro Vancouver providing nearly one-half of the cost directly and the remaining balance subject to external funding."

Once funding is in place, Metro Vancouver plans to move to the design phase in 2017, followed by equipment fabrication, with start-up occurring in 2018.

"If this emerging technology is a success, a future production facility could lead the way for Metro Vancouver's wastewater operation to meet its sustainability objectives of zero net energy, zero odours and zero residuals," Mussatto added.

In addition to the biocrude, the liquid phase can be treated with a catalyst to create other fuels and chemical products. A small amount of solid material is also generated, which contains important nutrients. For example, early efforts have demonstrated the ability to recover phosphorus, which can replace phosphorus ore used in fertilizer production.

Tuesday, October 18, 2016

Date: October 17, 2016Source: Duke UniversitySummary: Human-made chemical-laden fracking fluids make up less than 8 percent of wastewater being produced by fracked wells; more than 92% of it is naturally occurring brines, which carry their own risks but may have beneficial re-uses, say investigators.

Naturally occurring brines, not human-made fracking fluids, account for most of the wastewater coming from hydraulically fractured unconventional oil and gas wells, a new Duke University study finds.

"Much of the public fear about fracking has centered on the chemical-laden fracking fluids -- which are injected into wells at the start of production -- and the potential harm they could cause if they spill or are disposed of improperly into the environment," said Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment.

"Our new analysis, however, shows that these fluids only account for between 4 and 8 percent of wastewater being generated over the productive lifetime of fracked wells in the major U.S. unconventional oil and gas basins," Vengosh said. "Most of the fracking fluids injected into these wells do not return to the surface; they are retained in the shale deep underground.

"This means that the probability of having environmental impacts from the human-made chemicals in fracking fluids is low, unless a direct spill of the chemicals occurs before the actual fracking," he said.

More than 92 percent of the flowback and produced water -- or wastewater -- coming from the wells is derived from naturally occurring brines that are extracted along with the gas and oil.

These brines carry their own risks, Vengosh stressed. They contain varying levels of salts, heavy metals and naturally occurring radioactive elements, and their sheer volume makes disposing of them a challenge.

"But with proper treatment, they potentially could have beneficial reuses," he said, "especially out West, where our study shows most brines being produced by fracked wells are much less saline than those in the East. These Western brines, which are similar in salinity to sea water, could possibly be treated and re-used for agricultural irrigation or other useful purposes, especially in areas where freshwater is scarce and drought is persistent."

The Duke team published its findings Oct. 14 in the peer-reviewed journal Science of the Total Environment.

The researchers used three statistical techniques to quantify the volume of wastewater generated from unconventional oil and gas wells in six basins nationwide: the Bakken formation in North Dakota; the Marcellus formation in Pennsylvania; the Barnett and Eagle Ford formations in Texas; the Haynesville formation in Arkansas, Louisiana and East Texas; and the Niobrara field in Colorado and Wyoming.

Using multiple statistical techniques "helped us more accurately account for changes in each well's wastewater volume and salinity over time, and provide a more complete overview of the differences from region to region," said Andrew J. Kondash, a doctoral student in Vengosh's lab at Duke's Nicholas School, who led the study.

"This makes our findings much more useful, not just for scientists but for industry and regulatory agencies as well," he said.

Among other findings, the new study shows that the median volume of wastewater produced by an unconventional oil or gas well ranges from 1.7 to 14.3 million liters per year over the first five to 10 years of production. The volume of produced water coming from these wells declines over time, while its salinity increases.

"The salt levels rise much faster than the volume declines, resulting in a high volume of saline wastewater during the first six months of production," Vengosh said. After that, the volume of wastewater produced by a well typically drops, along with its hydrocarbon output.

Elizabeth Albright, assistant professor of the practice of environmental science and policy methods at the Nicholas School, co-authored the study with Kondash and Vengosh.

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Friday, October 14, 2016

Date: October 7, 2016Source: University of Colorado at BoulderSummary: Engineers have developed an innovative bio-manufacturing process that uses a biological organism cultivated in brewery wastewater to create the carbon-based materials needed to make energy storage cells. This unique pairing of breweries and batteries could set up a win-win opportunity by reducing expensive wastewater treatment costs for beer makers while providing manufacturers with a more cost-effective means of creating renewable, naturally-derived fuel cell technologies.

CU Boulder engineers have developed an innovative bio-manufacturing process that uses a biological organism cultivated in brewery wastewater to create the carbon-based materials needed to make energy storage cells.

This unique pairing of breweries and batteries could set up a win-win opportunity by reducing expensive wastewater treatment costs for beer makers while providing manufacturers with a more cost-effective means of creating renewable, naturally-derived fuel cell technologies.

"Breweries use about seven barrels of water for every barrel of beer produced," said Tyler Huggins, a graduate student in CU Boulder's Department of Civil, Environmental and Architectural Engineering and lead author of the new study. "And they can't just dump it into the sewer because it requires extra filtration."

The process of converting biological materials, or biomass, such as timber into carbon-based battery electrodes is currently used in some energy industry sectors. But, naturally-occurring biomass is inherently limited by its short supply, impact during extraction and intrinsic chemical makeup, rendering it expensive and difficult to optimize.

However, the CU Boulder researchers utilize the unsurpassed efficiency of biological systems to produce sophisticated structures and unique chemistries by cultivating a fast-growing fungus, Neurospora crassa, in the sugar-rich wastewater produced by a similarly fast-growing Colorado industry: breweries.

"The wastewater is ideal for our fungus to flourish in, so we are happy to take it," said Huggins.

By cultivating their feedstock in wastewater, the researchers were able to better dictate the fungus's chemical and physical processes from the start. They thereby created one of the most efficient naturally-derived lithium-ion battery electrodes known to date while cleaning the wastewater in the process.

The findings were published recently in the American Chemical Society journal Applied Materials & Interfaces.

If the process were applied on a large scale, breweries could potentially reduce their municipal wastewater costs significantly while manufacturers would gain access to a cost-effective incubating medium for advanced battery technology components.

"The novelty of our process is changing the manufacturing process from top-down to bottom-up," said Zhiyong Jason Ren, an associate professor in CU Boulder's Department of Civil, Environmental and Architectural Engineering and a co-author of the new study. "We're biodesigning the materials right from the start."

Huggins and study co-author Justin Whiteley, also of CU Boulder, have filed a patent on the process and created Emergy, a Boulder-based company aimed at commercializing the technology.

"We see large potential for scaling because there's nothing required in this process that isn't already available," said Huggins.

The researchers have partnered with Avery Brewing in Boulder in order to explore a larger pilot program for the technology. Huggins and Whiteley recently competed in the finals of a U.S. Department of Energy-sponsored startup incubator competition at the Argonne National Laboratory in Chicago, Illinois.

The research was funded by the Office of Naval Research and came as a result of a unique cross-disciplinary collaboration between Ren's lab in CU Boulder's Department of Civil, Environmental and Architectural Engineering; Professor Se-Hee Lee's lab in CU Boulder's Department of Mechanical Engineering; and Justin Biffinger's lab at the Naval Research Laboratory in Washington, D.C.

"This research speaks to the spirit of entrepreneurship at CU Boulder," said Ren, who plans to continue experimenting with the mechanisms and properties of the fungus growth within the wastewater. "It's great to see students succeeding and creating what has the potential to be a transformative technology. Energy storage represents a big opportunity for the state of Colorado and beyond."

Thursday, October 6, 2016

Date: March 18, 2016Source: Michigan State UniversitySummary: China's sweeping program to restore forests across the country is working. The vast destruction of China's forests, leveled after decades of logging, floods and conversion to farmland, has become a story of recovery, according to the first independent verification.

Much of the land in this Chinese community has been converted to forest from cropland through the government's Grain to Green program.Credit: Michigan State University Center for Systems Integration and Sustainability

China's sweeping program to restore forests across the country is working.

The vast destruction of China's forests, leveled after decades of logging, floods and conversion to farmland, has become a story of recovery, according to the first independent verification published in today's Science Advances by Michigan State University (MSU) researchers.

"It is encouraging that China's forest has been recovering in the midst of its daunting environmental challenges such as severe air pollution and water shortages," said co-author Jianguo "Jack" Liu, Rachel Carson Chair in Sustainability and director of MSU's Center for Systems Integration and Sustainability (CSIS). "In today's telecoupled world, China is increasingly connected with other countries both socioeconomically and environmentally. Every victory must be measured holistically, or we aren't getting a true picture."

Forests are crucial to ensuring soil and water conservation and climate regulation. The fate of forests in the world's most populous nation has global consequences by virtue of the country's sheer magnitude and its rapid development.

Since the beginning of the 21st Century, China has implemented the largest forest conservation andRecovering forests, with deforested areas in the background in Wolong China restoration programs in the world, the Natural Forest Conservation Program (NFCP), which bans logging, and in some forested areas compensates residents for monitoring activities preventing illegal timber harvesting.

The MSU scientists used a unique combination of data, including the big-picture view of NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) annual Vegetation Continuous Fields tree cover product, along with high spatial resolution imagery available in Google Earth. Then they combined data at different scales to correlate the status of the forests with the implementation of the NFCP.

And, as the Chinese government has contended, the program is working and forests are recovering, with about 1.6 percent, or nearly 61,000 square miles, of China's territory seeing a significant gain in tree cover, while 0.38 percent, or 14,400 square miles, experienced significant loss.

"Our results are very positive for China," said author Andrés Viña of MSU-CSIS. "If you look at China in isolation, its program is working effectively and contributing to carbon sequestration in accordance to its agenda for climate change mitigation. But on the other hand, China is not in a vacuum."

In the future, it is important to quantify how much China's forest gain and improved carbon sequestration may be a loss for places like Madagascar, Vietnam and Indonesia. Those are among the countries that are chopping down their forests to sell products to China. And the global increase in greenhouse gases and loss of biodiversity may have just changed addresses.

Viña noted more research is needed to document the broader impacts of forest degradation and recovery around the world. He also noted that the voracious appetite for natural resources -- both timber and the agricultural products grown on converted forestland -- is not just China's issue.

"We are all part of the problem one way or another," he said. "We all buy products from China, and China has not changed their imports and exports of wood at all. What has changed is where timber is coming from."

Besides Viña and Liu, "Effects of conservation policy on China's forest recovery" was written by MSU associate professor William McConnell, and CSIS PhD students Hongbo Yang and Zhenci Xu.

The work was supported by the National Science Foundation and MSU AgBioResearch.

Tuesday, August 9, 2016

Biological Mechanism for Health Benefits of Urban Greenery and on the Methodology to Expand Research Efforts

Date: August 2, 2016Source: University of OregonSummary: New research finds that airborne bacterial communities differ from one urban park to the next but those of parking lots are alike -- and differ from those of parks in subtle but potentially important ways.

Gwynne Mhuireach, a doctoral student in landscape architecture at the University of Oregon, check out a data-collection site at a park in Eugene, Oregon. Part of her project showed that using inexpensive petri dishes to collect air samples works as well as more expensive methods.Credit: University of Oregon

New research finds that airborne bacterial communities differ from one urban park to the next but those of parking lots are alike -- and differ from those of parks in subtle but potentially important ways.

At a glance, such findings seem intuitive. Parks often have different vegetation in them, and asphalt-covered parking lots are much the same -- barren asphalt bombarded by solar radiation as well as heavy metals and fuel from motor vehicles.

The importance, according to University of Oregon researchers, is that this pilot study describes not only the differences in microbial communities but also how far from a park the influence may extend.

Recent studies suggest that the composition of the bacterial communities may be important to human health -- and not in the ways you think, says Gwynne Mhuireach, a doctoral student in landscape architecture who led the new study that is online ahead of print in the journal Science of the Total Environment. There is a reason, she says, to believe that healthy air depends not just on the absence of bad things like pollutants, but the presence of good things such as bacteria with which humans have co-evolved.

"We're starting to build larger and more complex cities," Mhuireach said. "I am interested in ways to help maintain people's health and happiness as we do so. Some studies say that as we are building these denser cities we are losing green space. I am looking for mechanisms that explain why vegetation helps people and how we can design for it."

In the study, the researchers simultaneously collected six air samples over an eight-hour period at five parks and five parking lots in Eugene. The locations were free of tall trees that block air movement to constrain microbial differences due to air circulation -- another role vegetation may play. The idea, Mhuireach said, was to first discover whether vegetation was a significant source of microbes for nearby areas.

Subsequent DNA analyses found that Sphingomonas, commonly found in soil and on plant surfaces, accounted for one fourth of bacteria collected. Also abundant were Hymenobacter, Pedobacter, Agrobacterium and Rhodococcus, all soil-associated species. The samples were collected during the harvesting season of the grass-seed industry north of Eugene, when prevailing winds likely blew associated microbes into the sites, researchers noted.

Parking lots tended to be more similar to each other, with a prevalence of Acetobacteraceae, while parks had unique bacterial fingerprints likely reflecting vegetation types in and near each park.

The findings provide evidence of how differences in vegetation in an urban area influence airborne microbial communities at fine spatial scales, said co-author Bart Johnson, a professor of landscape architecture. The study, he said, provides a path to future studies that should help guide landscape design in cities where growing populations are driving denser living spaces.

While the specifics of how plant-associated microbes affect human health, and whether microbes contribute to the well-documented benefits of urban parks for people are unknown, the researchers suggest that "provisioning urban residents with green space within 400 meters (about 1,300 feet) of their homes" would make it more likely that they are exposed to the "park-like microbiome."

"There have been studies that compared the health of children who grow up on farms versus cities," Johnson said. "They've concluded that the lower incidence of allergies in children from farms was related to different microbial exposures, but there has been little work to examine whether there is enough microbial variation at the fine spatial scales of a park, a street or a block to potentially influence the health of children in cities.

"Do children and adults with greater exposure to vegetation receive increased health benefits because of the associated microbes? We don't know, but this study points to some promising new directions of inquiry," he said.

Equally important, the researchers documented that the simple use of petri dishes, a passive data-collection approach, successfully captured airborne microbial samples comparable to the more-expensive use of vacuum-powered equipment at the study sites.

"We just let air out of the sky settle into petri dishes and found that we can use this method in future projects because we found similar composition and diversity of microbes using both methods," Mhuireach said.

Mhuireach's research, Johnson said, creatively combines methodologies from biology, architecture and landscape architecture. It is reminiscent, he said, of Dr. John Snow's mapping of cholera outbreaks in the 1850s. Snow's work provided a scientific understanding of how the disease was spread by waterborne bacteria rather than by "bad vapors," and it coincided with the efforts of landscape architect Frederick Law Olmsted to incorporate nature into urban park designs to improve human well-being.

"Olmtead was dealing with invisible things -- then unknown -- that influenced people's health," Johnson said. "This new research is pointing to a biological mechanism behind Olmstead's ideas."

Mhuireach, who grew up on a farm, said she has been curious about health differences between people who grew up in rural and urban areas. She and her co-authors noted that while overall health has improved with technological progress and lifestyle changes, researchers have found that the shift away from childhood exposures to natural environments is associated with later-life inflammatory response problems such as allergies and asthma.

"As the research advances," she said, "we will be looking at vegetation around homes and neighborhoods where people live to start answering the big questions: Why does green space improve people's well-being? Are there physiological as well as psychological mechanisms? Are there beneficial microbes that we should be exposed to on a daily basis?"

Friday, July 1, 2016

Summary: New research indicates that California's Central Valley harbors three times more groundwater than previously estimated, but challenges to using it include pumping costs, ground subsidence and possible contamination from fracking and other oil and gas activities.

This image shows the California Aqueduct, with the Lost Hills Oil Field in the background.Credit: Rob Jackson, Stanford University

California's drought-stricken Central Valley harbors three times more groundwater than previously estimated, Stanford scientists have found. Accessing this water in an economically feasible way and safeguarding it from possible contamination from oil and gas activities, however, will be challenging.

"It's not often that you find a 'water windfall,' but we just did," said study co-author Robert Jackson, the Michelle and Kevin Douglas Provostial Professor at Stanford. "There's far more fresh water and usable water than we expected."

The research, published in the journal Proceedings of the National Academy of Sciences the week of June 27, highlights the need to better characterize and protect deep groundwater aquifers not only in California but in other parched regions as well.

"Our findings are relevant to a lot of other places where there are water shortages, including Texas, China and Australia," said study co-author Mary Kang, a postdoctoral associate at Stanford School of Earth, Energy & Environmental Sciences.

A Fresh Look at Groundwater

Previous estimates of groundwater in California are based on data that are decades old and only extend to a maximum depth of 1,000 feet, and often less. Until now, little was known about the amount and quality of water in deeper aquifers.

"Water a thousand feet down used to be too expensive to use," said Jackson, who is also a senior fellow at Stanford Woods Institute for the Environment and at the Precourt Institute for Energy. "Today it's used widely. We need to protect all of our good quality water."

Times are different now. California is in the midst of its fifth year of severe drought, and in 2014 Gov. Jerry Brown declared a drought emergency in the state. To meet its surface water needs, the state is increasingly turning to groundwater supplies.

In the new study, Jackson and Kang used data from 938 oil and gas pools and more than 35,000 oil and gas wells to characterize both shallow and deep groundwater sources in eight California counties.

The researchers concluded that when deeper sources of groundwater are factored in, the amount of usable groundwater in the Central Valley increases to 2,700 cubic kilometers -- or almost triple the state's current estimates.

Complications to Consider

While this is good news for California, the findings also raise some concerns. First, much of the water is 1,000 to 3,000 feet underground, so pumping it will be more expensive. Without proper studies, tapping these deeper aquifers might also exacerbate the ground subsidence -- the gradual sinking of the land -- that is already happening throughout the Central Valley. Groundwater pumping from shallow aquifers has already caused some regions to drop by tens of feet.

Furthermore, some of the deep aquifer water is also brinier -- higher in salt concentration -- than shallower water, so desalination or other treatment will be required before it can be used for agriculture or for drinking.

Another concern the Stanford scientists uncovered is that oil and gas drilling activities are occurring directly into as much as 30 percent of the sites where the deep groundwater resources are located. For example, in Kern County, where the core of California's oil and gas industry is centered near the city of Bakersfield, one in every six cases of oil and gas activities was occurring directly into freshwater aquifers. For useable water -- water that the U.S. Environmental Protection Agency deems drinkable if treated -- the number was one in three.

Jackson and Kang stress that just because a company has hydraulically fractured or used some other chemical treatment near an aquifer doesn't mean that the water is ruined.

"What we are saying is that no one is monitoring deep aquifers. No one's following them through time to see how and if the water quality is changing," Kang said. "We might need to use this water in a decade, so it's definitely worth protecting."

Friday, June 3, 2016

New research has detected smaller sulfur dioxide concentrations and sources around the world, including human-made sources such as medium-size power plants and oil-related activities.Credits: EPA

Using a new satellite-based method, scientists at NASA, Environment and Climate Change Canada, and two universities have located 39 unreported and major human-made sources of toxic sulfur dioxide emissions.

A known health hazard and contributor to acid rain, sulfur dioxide (SO2) is one of six air pollutants regulated by the U.S. Environmental Protection Agency. Current, sulfur dioxide monitoring activities include the use of emission inventories that are derived from ground-based measurements and factors, such as fuel usage. The inventories are used to evaluate regulatory policies for air quality improvements and to anticipate future emission scenarios that may occur with economic and population growth.

But, to develop comprehensive and accurate inventories, industries, government agencies and scientists first must know the location of pollution sources.

"We now have an independent measurement of these emission sources that does not rely on what was known or thought known," said Chris McLinden, an atmospheric scientist with Environment and Climate Change Canada in Toronto and lead author of the study published this week in Nature Geosciences. "When you look at a satellite picture of sulfur dioxide, you end up with it appearing as hotspots -- bull's-eyes, in effect -- which makes the estimates of emissions easier."

The 39 unreported emission sources, found in the analysis of satellite data from 2005 to 2014, are clusters of coal-burning power plants, smelters, oil and gas operations found notably in the Middle East, but also in Mexico and parts of Russia. In addition, reported emissions from known sources in these regions were -- in some cases -- two to three times lower than satellite-based estimates.

Altogether, the unreported and underreported sources account for about 12 percent of all human-made emissions of sulfur dioxide -- a discrepancy that can have a large impact on regional air quality, said McLinden.

The research team also located 75 natural sources of sulfur dioxide -- non-erupting volcanoes slowly leaking the toxic gas throughout the year. While not necessarily unknown, many volcanoes are in remote locations and not monitored, so this satellite-based data set is the first to provide regular annual information on these passive volcanic emissions.

"Quantifying the sulfur dioxide bull's-eyes is a two-step process that would not have been possible without two innovations in working with the satellite data," said co-author Nickolay Krotkov, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

First was an improvement in the computer processing that transforms raw satellite observations from the Dutch-Finnish Ozone Monitoring Instrument aboard NASA's Aura spacecraft into precise estimates of sulfur dioxide concentrations. Krotkov and his team now are able to more accurately detect smaller sulfur dioxide concentrations, including those emitted by human-made sources such as oil-related activities and medium-size power plants.

Being able to detect smaller concentrations led to the second innovation. McLinden and his colleagues used a new computer program to more precisely detect sulfur dioxide that had been dispersed and diluted by winds. They then used accurate estimates of wind strength and direction derived from a satellite data-driven model to trace the pollutant back to the location of the source, and also to estimate how much sulfur dioxide was emitted from the smoke stack.

"The unique advantage of satellite data is spatial coverage," said Bryan Duncan, an atmospheric scientist at Goddard. "This paper is the perfect demonstration of how new and improved satellite datasets, coupled with new and improved data analysis techniques, allow us to identify even smaller pollutant sources and to quantify these emissions over the globe."

The University of Maryland, College Park, and Dalhousie University in Halifax, Nova Scotia, contributed to this study.

For more information about, and access to, NASA's air quality data, visit:

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives, and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

Tuesday, May 17, 2016

A new study surveyed ecosystems of bacteria and their capacity to resist antibiotics in low-resource communities, including Pampas de San Juan de Miraflores, a densely populated slum outside Lima, Peru. (Photo: Pablo Tsukayama

Antibiotic-resistant bacteria most often are associated with hospitals and other health-care settings, but a new study indicates that chicken coops and sewage treatment plants also are hot spots of antibiotic resistance. The new study surveyed ecosystems of bacteria and their capacity to resist antibiotics in low-resource communities, including Pampas de San Juan de Miraflores, a densely populated slum outside Lima, Peru.

Antibiotic-resistant bacteria most often are associated with hospitals and other health-care settings, but a new study indicates that chicken coops and sewage treatment plants also are hot spots of antibiotic resistance.

The research, led by a team at Washington University School of Medicine in St. Louis, is published May 12 in Nature.

The scientists surveyed bacteria and their capacity to resist antibiotics in a rural village in El Salvador and a densely populated slum on the outskirts of Lima, Peru. In both communities, the researchers identified areas ripe for bacteria to shuffle and share their resistance genes. These hot spots of potential resistance transmission included chicken coops in the rural village and a modern wastewater treatment plant outside Lima.

"Bacteria can do this weird thing that we can't -- exchange DNA directly between unrelated organisms," said senior author Gautam Dantas, PhD, an associate professor of pathology and immunology. "That means it's relatively easy for disease-causing bacteria that are treatable with antibiotics to become resistant to those antibiotics quickly. If these bacteria happen to come into contact with other microbes that carry resistance genes, those genes can pop over in one step. We estimate that such gene-transfer events are generally rare, but they are more likely to occur in these hot spots we identified."

While the study was done in developing parts of the world, Dantas suggested ways the data could be relevant for the U.S. and other industrialized countries. If the chicken coops of subsistence farmers are hot spots of resistance gene transfer, he speculated that bacteria present in industrial farming operations -- where chickens regularly receive antibiotics -- would see even more pressure to share resistance genes. Dantas expressed concern about such bacteria getting into the food system. Further, the wastewater treatment facility the investigators studied in Lima is a modern design that uses technologies typical of such facilities around the world, including those in the U.S., suggesting these plants may be hot spots of antibiotic resistance transmission regardless of their locations.

The study is the first to survey the landscape of bacteria and the genetics of their resistance across multiple aspects of an environment, including the people, their animals, the water supply, the surrounding soil, and samples from the sanitation facilities. While the densely populated slum surrounding Lima has a districtwide sewage system and modern wastewater treatment plant, the village in El Salvador has composting latrines.

Rural villagers who rely on subsistence farming, and residents of densely populated, low-income communities surrounding cities make up a majority of the global population; yet their microbiomes are largely unstudied. Most similar studies to date have focused on heavily industrialized populations in the United States and Europe and on rare and so-called pristine communities of people living a traditional hunter-gatherer lifestyle.

"Not only do the communities in our study serve as models for how most people live, they also represent areas of highest antibiotic use," Dantas said. "Access to these drugs is over-the-counter in many low-income countries. Since no prescription is required, we expect antibiotic use in these areas to be high, putting similarly high pressure on bacteria to develop resistance to these drugs."

In general, Dantas and his colleagues found that resistance genes are similar among bacteria living in similar environments, with more genetic similarity seen between bacteria in the human gut and animal guts than between the human gut and the soil, for example. In addition, the researchers also found that bacteria that are closely related to one another have similar resistance genes, which might be expected as bacteria pass their genes from one generation to the next.

"The general trends we found are consistent with our previous work," Dantas said. "We were not terribly surprised by the resistance genes that track with bacterial family trees. On the other hand, the genes we found that break the hereditary trend are quite worrisome. Genes that are the exceptions to the rule -- that are not similar to the surrounding DNA -- are the ones that are most likely to have undergone a gene-transfer event. And they are the resistance genes at highest risk of future transmission into unrelated bacteria."

Of the locations sampled in the study, resistance genes that are most likely to be mobile and able to jump from one bacterial strain to another were found in the highest numbers in the chicken coops of villagers in El Salvador and in the outgoing "gray" water from the sewage treatment plant outside Lima. Not suitable for drinking, most of this water is released into the Pacific Ocean, and some is used to irrigate city parks, the researchers said.

"Soils in the chicken coops we studied appear to be hot spots for the exchange of resistance genes," Dantas said. "This means disease-causing bacteria in chickens are at risk of sickening humans and transferring their resistance genes in the process. Our study demonstrates the importance of public health guidelines that advise keeping animals out of cooking spaces."

As for the wastewater treatment plant, Dantas called it the perfect storm for transmitting antibiotic resistance genes. Such facilities are excellent at removing bacteria that are well-known for causing disease and can be grown in a petri dish, such as E. coli. But that leaves room for other types of bacteria to grow and flourish.

"The system is not designed to do anything about environmental microbes that don't make people sick," Dantas said. "But some of these bacteria carry resistance genes that are known to cause problems in the clinic. We are inadvertently enriching this water with bacteria that carry resistance genes and then exposing people to these bacteria because the water is used to irrigate urban parks."

Dantas and his colleagues suspect that the antibiotic resistance they measured in microbes that survive the plant's treatment process is driven by the presence of over-the-counter antibiotics in the sewage being treated. The researchers measured antibiotic levels before and after treatment, and while most of these drug residues are removed during the process, the fact that they're present at the beginning favors the survival of bacteria that are resistant to them.

"All the antibiotics we detected in the pre-treated water were among the top 20 sold in Peru," Dantas said. "These findings have implications for public health, perhaps in designing future wastewater treatment plants and in making policy decisions about whether antibiotics should be available without a prescription."

________________________________________

Story Source:

The above post is reprinted from materials provided by Washington University School of Medicine. The original item was written by Julia Evangelou Strait. Note: Materials may be edited for content and length.

Friday, April 8, 2016

Summary: Harmful algal blooms dangerous to human health and the Lake Erie ecosystem--such as the one that shut down Toledo's water supply for two days in 2014--could become a problem of the past. Scientists have reported on approaches to reduce harmful algal blooms on Lake Erie.

Jay Martin, an ecological engineer with The Ohio State University, poses next to the Maumee River in Toledo, Ohio, in this 2015 photo.Credit: Photo: Ken Chamberlain, CFAES.

Harmful algal blooms dangerous to human health and the Lake Erie ecosystem--such as the one that shut down Toledo's water supply for two days in 2014--could become a problem of the past.

A new report shows that if farmers apply agricultural best management practices (BMPs) on half the cropland in the Maumee River watershed, the amount of total phosphorus and dissolved reactive phosphorus leaving the watershed would drop by 40 percent in an average rainfall year -- the amount agreed to in the 2012 Great Lakes Water Quality Agreement between the U.S. and Canada.

Scientists believe that a drop of this magnitude would keep algal blooms at safe levels for people and the lake.

"With aggressive adoption of best management practices, it is possible to reduce harmful algal blooms to safe levels while maintaining agricultural productivity," said Jay Martin, ecological engineer in The Ohio State University's College of Food, Agricultural, and Environmental Sciences and co-author of the study.

The study, "Informing Lake Erie Agriculture Nutrient Management Via Scenario Evaluation," was a collaborative effort between the University of Michigan as the lead, The Nature Conservancy, Heidelberg University, LimnoTech, Texas A&M and Ohio State.

It reviewed 12 approaches to reducing total and dissolved reactive phosphorus and concluded that two of them would result in a 40 percent reduction on average.

"All 12 of the modeled scenarios produced results beneficial to phosphorus reduction," said Don Scavia, lead author of the study, environmental engineer and director of the University of Michigan's Graham Sustainability Institute.

Of the scenarios that reached the 40 percent threshold, one was an extreme approach unlikely to be implemented, Scavia said. That extreme approach showed that 1.5 million crop acres would need to be converted into grassland to meet the targets, if no additional BMPs were employed on agricultural lands.

On the other hand, "the most promising scenarios included widespread use of in-field and edge-of-field nutrient management practices, especially subsurface application of phosphorus fertilizers, expansion of cover crops and creation of buffer strips," he said.

The BMPs are practices farmers have successfully used for decades, said Martin, who also leads Ohio State's Field to Faucet water quality initiative. They include subsurface fertilizer application, cover crops, fertilizing according to soil tests and installing buffer strips to intercept runoff.

Solutions must be good for both water, farmers

"The BMP scenarios are more sustainable because they can sustain agricultural productivity while improving water quality," Martin said. "To move forward, it is most important to find solutions that both improve water quality and maintain economic returns for farmers."

In the most promising BMP scenario, about 1 percent of the land in the watershed, or about 30,000 acres, would need to be converted to buffer strips, and about half the farm acreage would need to have cover crops and subsurface phosphorus applications. Farmers in the watershed are already implementing some of these BMPs, and so are on the way to reaching the 50 percent adoption level that would be necessary, Scavia said. A scenario that included enhanced nutrient management on all the cropland was also effective in reaching this goal.

While the BMPs are familiar to farmers, "It's clear that broadening their use as much as needed will be a big lift," Martin said. "What will help is the additional $41 million that USDA announced it would invest in the Western Lake Erie Basin. This represents a significant investment that would help reach the 40 percent goal."

The U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS) announced theinvestment March 28 at Maumee Bay State Park near Toledo. The dollars will be used to support farmer implementation of conservation practices.

Funding will help implement best practices

"This, along with other innovative efforts like water trusts, cost shares, drain fee incentives, and public-private partnerships that are already underway within the Lake Erie Basin and other parts of the Great Lakes, provide examples of how to make this happen," Martin said.

"The challenge is how to integrate and scale up these and other parts of the solution to treat the number of acres needed to see measureable improvements in water quality," he said.

The researchers chose the Maumee watershed because it has the most impact on the Western Lake Erie Basin, where most of the dangerous algal blooms occur. Information from the study could likely be applied to other agriculturally dominated watersheds with similar slopes, soil types, crop rotations and drainage, Scavia said, but current BMP use would need to be determined.

"The study's models provided the best available advice on both the scale and direction of change needed to meet the new load targets, and they suggested multiple pathways for it. But, as with all modeling of this sort, they may have under- or overestimated what is needed," Scavia said.

"The real test is to begin implementing the change, tracking implementation progress, measuring environmental outcomes, and adjusting both the models and the actions if needed," he said.

Tuesday, March 22, 2016

Date: March 15, 2016Source:University of YorkSummary: Trace concentrations of antibiotic, such as those found in sewage outfalls, are enough to enable bacteria to keep antibiotic resistance, new research has found. The concentrations are much lower than previously anticipated, and help to explain why antibiotic resistance is so persistent in the environment.

Trace concentrations of antibiotic, such as those found in sewage outfalls, are enough to enable bacteria to keep antibiotic resistance, new research from the University of York has found. The concentrations are much lower than previously anticipated, and help to explain why antibiotic resistance is so persistent in the environment.

Antibiotic resistance can work in different ways. The research described the different mechanisms of resistance as either selfish or co-operative. A selfish drug resistance only benefits the individual cell with the resistance while a co-operative antibiotic resistance benefits both the resistant cell and surrounding cells whether they are resistant or not.

The researchers analysed a plasmid called RK2 in Escherichia coli, a bacterium which can cause infectious diarrhea. RK2 encodes both co-operative resistance to the antibiotic ampicillin and selfish resistance to another antibiotic, tetracycline. They found that selfish drug resistance is selected for at concentrations of antibiotic around 100-fold lower than would be expected -- equivalent to the residues of antibiotics found in contaminated sewage outfalls.

The study, which is published in Antimicrobial Agents and Chemotherapy (AAC), involved Professor Michael Brockhurst, Dr Jamie Wood and PhD student Michael Bottery in the Departments of Biology and Mathematics at York. The work was supported by the European Research Council under the EU's Seventh Framework Programme and the Wellcome Trust.

Dr Wood said: "The most common way bacteria become resistant to antibiotics is through horizontal gene transfer. Small bits of DNA, called plasmids, contain the resistance and can hop from one bacteria to another. Worse still, plasmids often contain more than one resistance."

Michael Bottery added: "There is a reservoir of antibiotic resistance out there which bacteria can pick and choose from. What we have found is some of that resistance can exist at much lower concentrations of antibiotic than previously understood."

Source: University of York. "Antibiotic resistance: it's a social thing." ScienceDaily. ScienceDaily, 15 March 2016. .

Friday, March 11, 2016

A new report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. Confidence is strongest in attributing types of extreme events that are influenced by climate change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event’s causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis. Read a 4-page summary of the report's findings and download the report for free.

Wednesday, January 6, 2016

Date: January 4, 2016Source:Asociación RUVIDSummary: A new type of concrete has been developed that is cheaper and much less polluting to the environment. Researchers have swapped in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.

Researchers from the Universitat Politècnica de València (Polytechnic University of Valencia, UPV) and San Paolo State University (Unesp) have developed a new type of concrete that is cheaper and much less polluting to the environment. They have done so by swapping in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.

Currently pursued at laboratory scale only, the results of this work have been published in the Construction and Building Materials journal. They also form part of Brazilian student João Cláudio Bassan de Moraes's master's dissertation, directed by lecturer Mauro Tashima, who completed his PhD at the UPV and is currently lecturing at Unesp.

Talking to us about the project, Jordi Payá, researcher at the Concrete Science and Technology Institute (ICITECH) at the UPV, explains: "The harvester strips the cane, discarding the tops and leaves as waste. This is the raw material we work with, sugar cane straw." In total around 650 million tonnes of sugar cane are harvested in Brazil every year. Of this, between 15 and 20% corresponds to sugar straw, which is left on the field and either burned or left to decay naturally.

So far, the international research team has been able to obtain concrete using 30% less Portland cement, substituting it with the ashes obtained from burning the sugar cane straw.

"The cement itself is the most expensive and most polluting ingredient of concrete, which makes the benefits [of this new method] as much economic as environmental. We are also making use of a by-product that is currently unexploited, with all the benefits that this entails" (Payá).

Process

To burn the waste, UPV and Unesp researchers have designed a bespoke combustion burner, into which the raw material must be fed following a strict procedure. "Through this process we obtain ashes that are very reactive to the cement, a quality that is very important to the mechanical performance of the resulting concrete, to its resistance to compression, for instance" (Payá).

Work has focused primarily on the microstructural analysis of the concrete. "In the lab we analyse the chemical compounds of the ashes and of the compounds produced during the reaction with the cement, in order to assess their performance in the final product," explains Payá. Future work would include studying indicators related to the durability of mass and reinforced concrete.

The ICITECH research team also studies the use of other agricultural waste as a cement substitute, including the bamboo leaf.

Story Source: The above post is reprinted from materials provided by Asociación RUVID.

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The American Academy of Environmental Engineering and Scientists is a not-for-profit 501(c)(6) organization serving the Environmental Engineering and Environmental Science professions by providing Board Certification to those who qualify through experience and testing. The Academy also provides training through workshops and seminars, participates in accrediting universities, publishes a periodical and other reference material, interacts with students and young professionals, sponsors a university lecture series, and rewards outstanding achievements through its international awards program.